University of Arkansas, Fayetteville ScholarWorks@UARK Theses and Dissertations 12-2018 A Tale of Two Butterflies: Theffec E t of Larval Social Environment and Circadian Rhythms on Mating Behavior in Bicyclus anynana and Heliconius hewitsoni Deonna Nicole Robertson University of Arkansas, Fayetteville Follow this and additional works at: https://scholarworks.uark.edu/etd Part of the Behavior and Ethology Commons, and the Entomology Commons Recommended Citation Robertson, Deonna Nicole, "A Tale of Two Butterflies: The Effect of Larval Social Environment and Circadian Rhythms on Mating Behavior in Bicyclus anynana and Heliconius hewitsoni" (2018). Theses and Dissertations. 3093. https://scholarworks.uark.edu/etd/3093 This Thesis is brought to you for free and open access by ScholarWorks@UARK. It has been accepted for inclusion in Theses and Dissertations by an authorized administrator of ScholarWorks@UARK. For more information, please contact [email protected], [email protected]. A Tale of Two Butterflies: The Effect of Larval Social Environment and Circadian Rhythms on Mating Behavior in Bicyclus anynana and Heliconius hewitsoni A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Biology by Deonna Nicole Robertson Henderson State University Bachelor of Science in Biology, 2013 December 2018 University of Arkansas This thesis is approved for recommendation to the Graduate Council. ___________________________________ Erica Westerman, Ph.D. Thesis Director ___________________________________ ___________________________________ Marlis Douglas, Ph.D. Adam Siepielski, Ph.D. Committee Member Committee Member ___________________________________ Neelendra Joshi, Ph.D. Committee Member Abstract Two key components of mate choice research focus on: 1) who an organism mates with, which may be influenced by any number of factors from sexual ornamentation to male-male competition; and, 2) when an organism courts, be it daily, monthly, or seasonally. Both aspects are especially important for gregarious species as mistakes in either can incur high costs to overall fitness. My research focuses on using butterflies to explore kin recognition from the larval stage and its possible impacts on adult mate choice and if courtship is circadian in Heliconius hewitsoni. My first experiment concerned kin recognition. When inbred, Bicyclus anynana are known to suffer from inbreeding depression, however populations can recover lost fitness within just a few generations when allowed to mate freely. It has been shown that B. anynana can recognize and choose against inbred individuals, however it is unknown whether they can detect siblings. I demonstrated that larval rearing condition (isolated or gregarious) did not influence adult mate choice in that female B. anynana did not innately detect or learn to detect and avoid sibling males during mate selection. Thus, in B. anynana, kin recognition may not be important to reproductive fitness. Through analysis of recorded behavior, I also showed that male harassment did not influence female mate choice. In my second experiment I examined circadian rhythms, specifically regarding courtship. I demonstrated that H. hewitsoni exhibits circadian rhythms, including a period of peak courtship around noon, and that some behaviors are sexually dimorphic in these butterflies. Recorded peak activity closely matches diurnal behavior in H. hewitsoni’s primary food source, which may influence overall behavior patterns in this species. My findings broaden our understanding of the mechanisms behind mate choice and provide valuable information for future research in these two systems, including the importance of female choice versus male harassment and sexual dimorphism in behavior. With my research I have improved our overall understanding of kin recognition and circadian rhythms to address the “who” and “when” of mate choice. ©2018 by Deonna Nicole Robertson All Rights Reserved Acknowledgements I find myself in a situation akin to an Oscar winner: I have too much to say, too many people to thank, and not enough time to do it in. There are so many people that helped make this body of work possible through their time, effort, and support. I cannot thank you all individually here, but there are several without whom I could not possibly have accomplished any of this, and their names deserve to be mentioned here. At the very top of my list is my advisor, Dr. Eric L. Westerman, who is one of the most amazing people I have ever known. To use a phrase from my mother’s book, you could say that I “think she hung the moon.” This gracious, patient, understanding woman took me on as a graduate student an entire year ahead of schedule and made room for me in her lab when she did not have to. I fondly remember leaving our very first meeting excited by the idea of graduate school in a way that I had not been in a very long time. We established two things at the end of that meeting; a repeat appointment for the next week and my assignment for that appointment. I had homework for a meeting! What a concept! At any rate, that faithful day in August marked the beginning of our journey together, and I have loved the opportunity to study and learn under her tutelage. Dr. Westerman, wherever I may go from here, I cannot begin to thank you enough for everything you have done for me and I will never forget any of it. Words can never truly express the immense gratitude I feel for you and your willingness to take a chance on me. From the bottom of my heart, thank you. I would also like to thank my thesis committee members, Marlis Douglas, Adam Siepielski, and Neelendra Joshi. Foremost, thank you for agreeing to be on my committee in the first place. I was very fortunate to get all three of my first picks for my committee, and I was absolutely delighted by every “yes” that came my way. I greatly appreciate your time and effort in making this thesis the best it can be. I found your questions insightful and your comments helpful, and I am very happy to have worked with you all. Next, I absolutely must thank my labmates, Dylan Myer, Grace Hirzel, Matthew Murphy, and Tim Sullivan. I could not have done it without your support, I know that beyond a shadow of a doubt. Dylan, you were one of the first in the lab, along with me. Your jolly attitude and willingness to let me yammer for hours on end while we worked to get the greenhouse in shape or build large butterfly cages was wonderful. Though you have moved on from the lab, you are not forgotten, and I am thankful to have known you. Grace, you are probably my best friend in the lab, and the emotional support you have given me, along with hours of advice and conversation over tea or coffee or hanging pupa has been invaluable. I look forward to what will hopefully be many, many more years of friendship and gallons of hot beverages. Matt, bless your patience and your clarity! You got me started on R coding, and that phrase does not at all reflect the might of the task you accomplished. I hope that I was not a difficult student and I am so grateful for your help. Tim, your comments on my presentations were so helpful, and I very much enjoyed working with you. May the road you now travel be a smooth one. You guys were awesome! Thanks! Right behind my labmates are my family. Mom, Dad, Josh, Jess, Anthony, Aunt Christie, Uncle Tommy, and Grandmama, you guys get top billing for sure! I could never have made it this far in life, let alone school, without you. Your support has meant the world to me. I hope I make you as proud of me as I am of all of you. I love you guys. And, Anthony? Aunt Nikki can play with you again real soon. The directors, staff, and players of Dystopia Rising: Arkansas provided one of my largest, loudest emotional support networks, and you all helped me blow off steam when the pressure was highest. The sheer number of you who went out of your way to check on me when you noticed I was stressed, celebrated the end of my data collection with me, or dropped out of character in the middle of game to ask me how all of it was going is just staggering. I cannot thank all of you enough for your kind and encouraging words. I am because you are. While we are in the emotional support category, I also need to thank Brooke Howard-Parker, Steven Maulden, and my two dogs, Harley and AJ. Brooke, I knew I wanted to be your friend two seconds after meeting you. You helped keep me on track while I was here, helped me get my office, and kept me laughing even when things got tough. Your sage advice and willing ear have been such a joy to me. You are one amazing woman! Never let anything douse your fire. Steven, sometimes I think you came along at both the worst and best time for both of us, but I could not have asked for a more understanding partner. Your insight into graduate school and all of the challenges that come with it has been so helpful, both to me and to our relationship. The support you’ve given me throughout this work was so important, and I thank you profusely for it, my Owl. Harley and AJ, you kept my feet warm, provided me with all the snuggles I could handle, and helped me get up in the morning. My angry old lady and my big neurotic mess. I love you both! Finally, last but certainly not least, I need to thank my best friend and roommate, Kelley Jean Sweet.